Studies Of Influencing Factors Of UFD Produced In Detonation And Its Purification Techniques

free carbon produced in detonation of high density negative – oxygen –balance explosive transforms into UFD on the condition of high temperature and high pressure. The factors influencing the detonation synthesis, which include explosive component proportion , charge diameter, constraint condition and preservative medium, have been studied. It is shown that in this experimental condition , the optimal mass ratio of TNT and RDX is 55.5 to 44.5. Charge diameter plays an important role in the detonation synthesis. The optimal diameter is 32mm. Yield of UFD is improved with increasing of the mass of preservative medium, but becomes independent of the mass until it reaches a certain degree. Constraint condition is advantage of the yield of UFD too. The pressure–time relationgship in detonation and expansion process in different charge , constraint and preservative medium conditions are numerically simulated. The simulation results are in good agreement with experimentation. XRD, TEM, FTIR, TG,DTA and particle-size analysis are conducted to characterize the produced ultrafine diamond. The methods of purification are investigated too. Vapour phase oxidation purification in high temperature is applied for the first time and optimal processing temperature is gained from weight losses. Oxidation purification alleviates environmental pollution and is of economical and social benefits .